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Journal articles
Population genetic structure and isolation by distance of Helicobacter pylori in Senegal and Madagascar.
Abstract : Helicobacter pylori has probably infected the human stomach since our origins and subsequently diversified in parallel with their human hosts. The genetic population history of H. pylori can therefore be used as a marker for human migration. We analysed seven housekeeping gene sequences of H. pylori strains isolated from 78 Senegalese and 24 Malagasy patients and compared them with the sequences of strains from other geographical locations. H. pylori from Senegal and Madagascar can be placed in the previously described HpAfrica1 genetic population, subpopulations hspWAfrica and hspSAfrica, respectively. These 2 subpopulations correspond to the distribution of Niger-Congo speakers in West and most of subequatorial Africa (due to Bantu migrations), respectively. H. pylori appears as a single population in Senegal, indicating a long common history between ethnicities as well as frequent local admixtures. The lack of differentiation between these isolates and an increasing genetic differentiation with geographical distance between sampling locations in Africa was evidence for genetic isolation by distance. The Austronesian expansion that started from Taiwan 5000 years ago dispersed one of the 10 subgroups of the Austronesian language family via insular Southeast Asia into the Pacific and Madagascar, and hspMaori is a marker for the entire Austronesian expansion. Strain competition and replacement of hspMaori by hpAfrica1 strains from Bantu migrants are the probable reasons for the presence of hspSAfrica strains in Malagasy of Southeast Asian descent. hpAfrica1 strains appear to be generalist strains that have the necessary genetic diversity to efficiently colonise a wide host spectrum.
Keywords :
Helicobacter Infections/genetics
Geography/methods
GeneticsPopulation/methods
Genetic Variation/genetics
Aged 80 and over
Aged
African Continental Ancestry Group/genetics
Madagascar
Middle Aged
Phylogeny
Population Groups/genetics
Senegal
Young Adult
Adolescent
Humans
Human Migration
Helicobacter pylori/isolation & purification
Helicobacter pylori/genetics
Helicobacter Infections/microbiology
Adult
Cited literature [41 references]
https://hal-riip.archives-ouvertes.fr/pasteur-01078450
Contributor : Princy Rakotoarison Connect in order to contact the contributor
Submitted on : Wednesday, October 29, 2014 - 9:27:44 AM
Last modification on : Monday, November 22, 2021 - 5:46:02 PM
Long-term archiving on: : Friday, January 30, 2015 - 10:12:07 AM
Contributor : Princy Rakotoarison Connect in order to contact the contributor
Submitted on : Wednesday, October 29, 2014 - 9:27:44 AM
Last modification on : Monday, November 22, 2021 - 5:46:02 PM
Long-term archiving on: : Friday, January 30, 2015 - 10:12:07 AM
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